• Journal of Korea Entertainment Industry Association
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• v.14 no.6
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• pp.269-277
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• 2020

The purpose of this study is to investigate the recovery of sensation and the restoration of upper limb function according to transcranial direct current stimulation over the primary somatosensory cortex in patients with chronic stroke with sensory deficit. 20 patients with chronic stroke divided into 10 experimental groups and 10 control groups. Patients received transcranial direct current stimulations over the primary somatosensory cortex on the side of the stroke lesion, and The control group applied sham tDCS to the same location. Intervention was conducted 5 times a week, 20 minutes per session for a total of 2 weeks. Assessment was performed using the Erasmus MC modifications to the Nottingham Sensory Assessment(EmNSA), Semmes-Weinstein monofilament examination(SWME) for somatosensory, and Fugle-Meyer Assessment(FMA), Motor Activity Log(MAL), and accelerometer for upper extremity function. Assessment was conducted before and after the intervention. As a result of the study, the experimental group showed a significant improvement in the overall tactile sense, proprioception, cortical sense, and perception sensitivity than the control group, and showed a statistically significant difference in the usage amount of the upper limb. Based on the results of this study, it is thought that the possibility of effective clinical application of transcranial direct current stimulation for recovery of somatosensory and upper extremity function is thought to be increased.

• The Journal of Korean Physical Therapy
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• v.22 no.4
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• pp.97-101
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• 2010

Purpose: Sensory input is very important for proper performance of human. Two-point discrimination is the most widely used tactile sensory test. The purpose of this study was to find the changes in cortical activation patterns between tactile stimulation and two-point discrimination. Methods: Two healthy subjects participated in our study. fMRI scanning was done during 4 repeated blocks of tactile stimulation and two point discrimination of the right index finger tip. In one block, stimuli were repeated 10 times every three seconds. To determine the changes of cortical neurons during sensory input, intensity index was analyzed. Results: When tactile stimulation of the right index finger tip was completed, only contralateral primary somatosensory area was activated. In contrast, during two-point discrimination, both the primary somatosensory area and ipsilateral supplementary sensory area were activated. Conclusion: During two point discrimination, both primary somatosensory area and ipsilateral supplementary sensory area were activated. Therefore, two-point discrimination is required more complex and conscious activity than tactile stimulation.

• The Korean Journal of Physiology
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• v.28 no.1
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• pp.99-103
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• 1994

Single neuronal activities were recorded in the cuneate nucleus of awake rats during rest and running behavior. Movement-induced changes in somatic sensory transmission were tested by generating post-stimulus time histograms of these neurons' responses to stimulation through eleetrodes chronically implanted under the skin of the forepaw, during control resting behavior and during two standardized speeds of locomotor movement: slow (1.0 steps/s), fast (2.0 steps/s). The magnitudes of firing during these responses were measured and normalized as percentage increases over background firing. The averaged evoked unit responses were facilitated by $+59.3{\pm}12.5%\;and\;+25.6{\pm}5.4%$ (SEM) as compared with resting behavior, during slow and fast movement respectively. This is to be compared with the movement-induced sensory suppressions observed previously in the ventrobasal thalamus $(-31.0%{\pm}1.9%)$ and in the primary somatosensory cortex $(-71.2%{\pm}3.8%)$ of slowly running rats. These results suggest that afferent somatosensory information may be uniquely modulated at each sensory relay, such that it may be facilitated at brainstem level and then subjected to suppression at higher somatosensory nuclei during movement.

• Journal of Biomedical Engineering Research
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• v.32 no.2
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• pp.93-104
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• 2011

The purpose of this study was to investigate lower-limb joint torque of the two groups as it changed by somatosensory stimulation during the descent down three stairs of different heights and to describe the difference between the two groups, which are young people group and elderly people group. Subjects of each groups climbed down a stair at four stimulation conditions, which are non-stimulation, tibialis anterior tendon stimulation, achilles tendon stimulation, tibialis anterior - achilles tendon stimulation. Motion capture data were collected using 3D optoelectric motion tracking system that utilizes active infrared LEDs, near infrared sensor and force plate. The obtained motion capture data was used to build 3D computer simulation model. The results show that lower-limb joint torque of the two groups changed with somatosensory stimulation as they descended the stairs and the joint torque of the two groups differed from each other.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.89-96
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• 2019

Objective: The purpose of this study was to investigate biomechanical comparisons of kettlebell two-arm swings after different somatosensory interventions on joint ranges of motion (ROM) and muscle activations. Method: Fourteen kettelbell novices (age: $22.92{\pm}3.23yrs$, mass: $75.75{\pm}9.94kg$, height: $172.03{\pm}5.49cm$), consisting of male college students, participated in this study and performed two-arm kettlebell swings in different conditions. Three different somatosensory interventions were the applications of heavy mass kettlebell (20 kg), taping on gluteus muscles, and unstable mat condition. All subjects performed pre-intervention swings and post-intervention swings, respectively. Statistical analysis were performed on results of joint kinematics and electromyographies of major muscles. Results: Results showed significant increases in ROM of hip and decreases in ROM of shoulder after unstable mat trials. In addition, the application of unstable mat during kettlebell swings induced higher muscle activations in gluteus maximus muscle during only upward phase of two-arm kettlebell swings. Conclusion: For beginner, the application of unstable surface would increase in hip joint ranges of motion with enhancement of gluteus muscles.

• Physical Therapy Korea
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• v.27 no.2
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• pp.126-132
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• 2020

Background: Augmented somatosensory feedback stimulates the mechanoreceptor to deliver information on bodily position, improving the postural control. The various types of such feedback include ankle-foot orthoses (AFOs) and vibration. The optimal feedback to mitigate postural sway remains unclear, as does the effect of augmented somatosensory feedback on muscle co-contraction. Objects: We compared postural sway and ankle muscle co-contraction without feedback (control) and with either of two forms of somatosensory feedback (AFOs and vibration). Methods: We recruited 15 healthy subjects and tested them under three feedback conditions (control, AFOs, vibration) with two sensory conditions (eyes open, or eyes closed and the head tilted back), in random order. Postural sway was measured using a force platform; the mean sway area of the 95% confidence ellipse (AREA) and the mean velocity of the center-of-pressure displacement (VEL) were assessed. Co-contraction of the tibialis anterior and gastrocnemius muscles was measured using electromyography and converted into a co-contraction index (CI). Results: We found significant main effects of the three feedback states on postural sway (AREA, VEL) and the CI. The two sensory conditions exerted significant main effects on postural sway (AREA and VEL). AFOs reduced postural sway to a level significantly lower than that of the control (p = 0.014, p < 0.001) or that afforded by vibration (p = 0.024, p < 0.001). In terms of CI amelioration, the AFOs condition was significantly better than the control (p = 0.004). Vibration did not significantly improve either postural sway or the CI compared to the control condition. There was no significant interaction effect between the three feedback conditions and the two sensory conditions. Conclusion: Lower-extremity devices such as AFOs enhance somatosensory perception, improving postural control and decreasing the CI during static standing.

• Progress in Medical Physics
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• v.17 no.3
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• pp.159-166
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• 2006

The nonlinearity of hemodynamic response in the somatosensory cortex was investigated with vibrotactile stimulation. The stimuli consisted of a train of 25 Hz, each tasting five different duration periods, 2 s, 4 s, 8 s 12 s, or 16 s with 20 sec periods of no vibration in a pseudo-random order. In order to understand the linearity on the change of stimulus duration for somatosensory cortex, two different tests- checking the linearity of system and finding the impulse response function from gamma-variate function were applied to analyze the hemodynamic response functions. They have produced nearly same results. The BOLD response in the somatosensory cortex Is nonlinear for stimuli of less than 8 seconds, but nearly linear for stimuli greater than 8 seconds. The amplitude, area, TTP, and FWHM as functions of the stimulus duration were calculated and showed a significant downward trend with Increasing stimulus duration for the amplitude and the area. It supports the ranges of nonlinearity are less than 8 seconds.

• Physical Therapy Korea
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• v.23 no.1
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• pp.87-93
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• 2016

Background: Posture balance control is the ability to maintain the body's center of gravity in the minimal postural sway state on a supportive surface. This ability is obtained through a complicated process of sensing the movements of the human body through sensory organs and then integrating the information into the central nervous system and reacting to the musculoskeletal system and the support action of the musculoskeletal system. Motor function, including coordination, motor, and vision, vestibular sense, and sensory function, including proprioception, should act in an integrated way. However, more than half of stroke patients have motor, sensory, cognitive, and emotional disorders for a long time. Motor and sensory disorders cause the greatest difficulty in postural control among stroke patients. Objects: The purpose of this study is to determine the effect of visual and somatosensory information on postural sway in stroke patients and carrying out a kinematic analysis using a tri-axial accelerometer and a quantitative assessment. Methods: Thirty-four subjects posed four stance condition was accepted various sensory information for counterbalance. This experiment referred to the computerized dynamic posturography assessments and was redesigned four condition blocking visual and somatosensory information. To measure the postural sway of the subjects' trunk, a wireless tri-axial accelerometer was used by signal vector magnitude value. Ony-way measure analysis of variance was performed among four condition. Results: There were significant differences when somatosensory information input blocked (p<.05). Conclusion: The sensory significantly affecting the balance ability of stroke patients is somatosensory, and the amount of actual movement of the trunk could be objectively compared and analyzed through quantitative figures using a tri-axial accelerometer for balance ability.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.4
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• pp.587-596
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• 2010

Purpose : This study was performed to investigate the effects of somatosensory training on the spatiotemporal gait parameters and balance in patients with stroke patients. Methods : 24 stroke survivors were allocated in this study, and randomly divided into experimental(n=12) and control group(n=12), independently. Experimental group was applied somatosensory training program plus conventional physical therapy, and control group was applied only conventional physical therapy. All subjects were administered for 30 minutes per day during 8 weeks(5 times a week). Results : Spatiotemporal parameters of gait were significant difference between pre and post intervention in experimental group, except of step length asymmetry ratio(SLAR) and single support time asymmetry ratio (SSAR)(p<.05). But control group had no statistical significance(p>.05). And also there was significant difference between experimental and control group(p<.05), except of cadence and SSAR(p>.05). Balance parameters were significant difference between pre and post intervention in experimental group(p<.05). But control group had no statistical significance(p>.05). And experimental timed up and go test was significantly decreased than control group(p<.05), but berg balance scale and functional reach test were not significant difference between experimental and control group(p>.05). Conclusion : This study was suggested that somatosensory training has effectiveness on the spatiotemporal gait parameters and balance in patients with stroke survivors. So this therapeutic intervention will be effectivelyapply to the stroke survivors in the clinical setting.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.6
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• pp.651-656
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• 2011

Although prosthetic training was received, most of amputees mainly depend on visual feedback to use prostheses, not on cutaneous and proprioceptive sensibility. Our objective of this study was to determine if there are changes in the somatosensory sensibility of amputees compared to non-amputees using multi-channel vibration stimulation system. One transradial amputees and ten non-amputees were involved. To investigate changes of residual somatosensory sensibility at stump, we set up custom-made vibration stimulation system including eight actuators (4 medial and 4 lateral) and GUI-based acquisition system. The results showed that there was similar pattern of subjective response at most of channels among group as stimulation increases. However, amputees' subjective response at channel 8 for 238Hz vibration was more sensitive than that of healthy persons. With respect to channels, response at channel 4 (medial) corresponding region to flexor carpi ulnaris for transradial amputees was most sensitive than other channels. In addition, sensitivity of four medial channels was on average about 0.5 scale than that of four lateral channels. Somatosensory sensibility was amputee, women, and men in sensibility order.